api中的foreach obj如何发出另一个请求

Question

my first post req looks like

this.http.post('http://localhost:8080/api/userfilm/get/', {
      name: this.name })

and he returns array of objects with property named filmid. my second post request looks like

this.http.post('http://localhost:8080/api/post/get/', {
        filmid: film.filmid })

i really dont know how i can do this one by one. for example

getAllPosts() {
    return this.http.post('http://localhost:8080/api/userfilm/get/',
        { name: this.name })
    .flatMap((film: any) => 
        this.http.post('http://localhost:8080/api/post/get/', 
        { filmid: film.filmid }))
    }


this.getAllPosts().subscribe(response => {
        console.log(response);
      })

but this is not returns corretly

Answer 1

You can implement like this

this.http.get("https://jsonplaceholder.typicode.com/users")
      .map(res => res.json())
      .mergeMap((customers: any[]) => {
        if (customers.length > 0) {
          return Observable.forkJoin(
            customers.map((customer: any) => {
              return this.http.get('https://jsonplaceholder.typicode.com/users/' + customer.id)
                .map((res: any) => {
                  return res.json();
                });
            })
          );
        } else {
          return Observable.of([]);
        }
      }).subscribe(res => console.log(res));